Prain .- — The Mercurialinecte and 
386 
there is a close affinity between Mercurialis and Seidelia. But between 
Adenocline and Seidelia there is little external resemblance and even less 
affinity ; Adenocline belongs to the Gelonieae, Seidelia to the Acalypheae. 
The nearest relationship of Seidelia is with the genus Leidesia. Both 
agree with Mercurialis in their simple styles, 2-coccous capsule, and 
valvately partite male calyx ; both differ from Mercurialis in having 
alternate, not opposite leaves ; both are usually monoecious, Mercurialis is 
usually dioecious. They differ from each other because in Seidelia the 
anthers are cruciately 4-valved and the female calyx and hypogynous disc- 
glands are well developed, while in Leidesia the anthers are 2-valved and 
the female calyx and hypogynous disc-glands are usually small or obsolete. 
In Seidelia the capsules are glabrous ; in Leidesia they are setulose. 
Review of Leidesia. 
The genus Leidesia was founded by Muller in 1866 (DC. Prodr., xv. 2, 
792) to include two South African species. One is the plant which Linnaeus 
named Mercurialis androgyna in 1737, M. procumbens in 3753, and Croton 
Ricinocarpos in 1763. The other is the plant described by Thunberg 
in 1823 as Acalypha obtusa (Flor. Cap., ed. Schult., 546). The history of 
the first species has been recounted. The second species has a brief 
history ; it never was formally transferred from Acalypha . This, however, 
is not because the plant is an Acalypha , but because Sonder in 1850 
(Linnaea, xxiii. 112) and Baillon in 1862 (Adansonia, iii. 158) did not 
separate these two South African congeners. 1 
Since the word Leidesia is an anagram of the name Seidelia (DC. 
Prodr., xv. 2, 793) it is probable that, when he devised the name Leidesia , 
Muller thought Seidelia a valid genus, the transfer of which to Tragia was 
a sudden, as well as an unhappy afterthought. A possible sequel of this 
afterthought is the citation by Muller under Leidesia of ‘ Mercurialis, sect. 
Seidelia, Baill., Rec. d’obs. bot., vol. 3, p. 158 pr. p. et p. 1 75 pr. p. * (1. c., 792). 
This reduction contradicts the citation of ‘ Mercurialis, sect. Seidelia * as 
a whole, under Tragia , sect. Seidelia (l.c., 947). That the citation at 
p. 792 is a lapsus we learn from a third passage (1. c., 3:141) where the correct 
name ‘ Mercurialis, sect. Trismegista’ is used. 
Of the three names applied by Linnaeus to the first species on which the 
genus Leidesia is based, Muller only associated the last one with this plant 
with 2-coccous capsules ; the first name he associated with an American, the 
second name with an African species, both of which have 3-coccous capsules. 
Even as regards the third name Muller decided that it must be set aside. 
1 In 1843 E. Meyer (Drege, Zwei Pfl. Documente, 201) also aggregated the two species of 
Leidesia y and united both with a 3-coccous plant which he had named Mercurialis tricocca. 
The same amalgamation was repeated by Baillon in 1858 (Etud. g£n. Euphorb., 457) under the 
name Adenocline Mercurialis , Baill. non Turcz. 
